Measuring the health of Mt. Tam

Maintaining a healthy, vibrant and diverse Mt. Tam begins with understanding how key ecological resources are faring, and how we can better care for this iconic and beloved place.

One Tam partners and Bay Area scientists have come together to try to answer the question: How healthy are Mt. Tam's natural resources?

Current and Past Natural Resource Management

Stewardship and management activities of varying scales have been underway for decades within the One Tam area of focus. The summary of current and past activities listed below is by no means a comprehensive list, but is intended to provide a sense of the type and scale of work that has been undertaken to monitor, protect, and restore important health indicators.

Overarching Vegetation Management and Monitoring Efforts

Several large-scale programs manage or track plant communities and species on Mt. Tam.

Weed Monitoring, Surveying, and Management

One Tam staff and partner agencies survey roads, trails, facilities, and recently disturbed sites for priority invasive plant species. Although surveys are conducted year round, most occur between March and September. Survey areas are prioritized based on their rates of human use and on habitat health, with a goal of surveying all roads and trails every three to five years.

NPS surveys began in 2008, with other land managers launching their programs in subsequent years. One Tam initiated surveys in 2016 to add capacity to partner agency efforts.

Large-Scale Weed Management Program

One Tam partner agencies commit significant resources to mapping, monitoring, and managing invasive vegetation on their lands. Full-time and seasonal staff, as well as interns, are dedicated to providing volunteer management and leading these stewardship activities.

Land managers also rely on contract labor to map and control targeted invasive plant populations. Wide Area Fuelbreak projects on both MMWD and MCP lands are implemented by contractors for both fuels management and resource enhancement. In 2012, NPS and State Parks staff launched comprehensive watershed-wide target invasive plant management in the Redwood Creek Watershed with the help of staff, contractors, and volunteers.

Rare Plant Monitoring

Mt. Tam supports more than 40 rare, threatened, and endangered plant species. Location and population data is available for many of these species through field surveys conducted by One Tam land managers and partners including the California Native Plant Society (Marin Chapter).

The scale of each monitoring program varies based on staff and volunteer resources. For example, NPS staff conducts annual rare plant monitoring, with individual populations visited once every three to five years; however, MMWD staff are in the process of re-inventorying their rare plant populations and have updated data on approximately 80% of the over 400 individual patches on watershed lands within the past five years.

Plant Community Monitoring

NPS staff monitors the structure and composition of redwood forest and coastal scrub plant communities at Bolinas Ridge, Muir Woods, and Green Gulch. This long-term monitoring program began in 2015, and randomly located, permanent vegetation plots will be revisited once every four years. Periodic trend analyses will help reveal community dynamics (succession, temporal variability, etc.), and examine correlations between climate change, land use, and biological interactions.

Coast Redwood Forests

Old Growth:

Muir Woods and Steep Ravine:

(1) Ongoing, systematic invasive plant mapping and management on varying scales at Muir Woods for over three decades, and invasive species management and increasing Early Detection and Rapid Response work in Steep Ravine—target species include yellow star thistle, and Scotch and French brooms, cape ivy, pampas grass, licorice plant, and panic veldt grass; (2) Expansion of this program in 2012 through NPS-supported crews working Redwood Creek Watershed-wide, and One Tam crews focusing on detection and treatment work at Steep Ravine

Muir Woods:

(1) Installed more than 14,000 native plants to revitalize disturbed and compacted redwood understory habitat; (2) Converted asphalt trails to raised boardwalks to reduce compaction and guide visitor access; (3) Established boot-washing stations to reduce the risk of Phytophthora spread; (4) Conducted an inventory to assess canopy health and species richness; (5) Reduced the entrance parking lot size and converted part of it to a plaza; (6) Raised the Hillside Trail in Muir Woods above the fragile redwood root system; (7) Collected LiDAR data to create topographic, stream channel, and tree canopy maps of Muir Woods and Kent Canyon which will help track changes to the forest over time

Second-growth:

The Resilient Forest Project: A series of forest treatment trials to identify ways to improve forest function and strengthen areas with high levels of SOD-related hardwood mortality, including approximately 20 acres of redwood-tanoak forest initiated in 2015 and scheduled to continue for at least five years (MMWD and UC Davis)

Sargent Cypress

Mapping and Inventories: Periodic vegetation community mapping and ongoing Early Detection and Rapid Response (MMWD)

Open-canopy Oak Woodlands

Restoration: (1) Succession management: Volunteer restoration workdays held to pull broom and cut encroaching Douglas-fir saplings in some areas, with additional conifer removal done by staff and contractors; (2) Wide Area Fuelbreak project at Pine Point: A joint project by MMWD and Youth2Work that removed Douglas-fir and non-native pine invading oak woodlands and grasslands and replaced Douglas-fir with native SOD-resistant oaks to meet both ecosystem and fuels reduction goals

Monitoring: (1) Aerial photo monitoring and interpretation of vegetation communities repeated every five years to examine SOD distribution and impact (MMWD); (2) Invasive plant species early detection mapping and monitoring (MMWD, NPS, and MCP)

Outreach: Partnership with UC Cooperative Extension on public outreach to build awareness about SOD spread, impacts, and risk reduction measures

Maritime Chaparral

Monitoring: Rare plant surveys within Golden Gate National Recreation Area lands on Bolinas Ridge every one to three years (as resources allow) focused on confirming and mapping presence of previously recorded individual rare plants and searching for new occurrences in suitable habitat (NPS)

Conservation: Mason’s ceanothus and Marin manzanita seedbanked as part of the California Native Plant Society’s “Rare Plant Rescue” program in 2015 (MMWD)

Grasslands

Restoration: (1) Volunteer workdays to pull weeds and cut Douglas-fir in some areas; (2) Succession management: additional conifer and weed removal, plus some coyote bush cutting and mowing by staff and contractors (MMWD and State Parks); (3) Grassland protection (removal of erosion gullies, re-alignment of trail, planting of grassland species) as a part of the Dias Ridge trail corridor re-alignment process; (4) Wide Area Fuelbreak project at Pine Point (MMWD) to maintain open grassland and oak woodlands included succession management (removal of Douglas-fir and coyote brush)

Mapping/Monitoring: Completed an analysis of species richness, spatial extent and stressors for approximately 185 grassland patches within Mount Tamalpais State Park to prioritize restoration actions (State Parks and UC Berkeley)

Serpentine Barrens

Anadromous Fish

Restoration: (1) Extensive habitat restoration in Lagunitas Creek including installing large wood structures and reducing fine sediment inputs (MMWD); (2) Redwood Creek habitat restoration including removal of fish passage barriers, installation of habitat structures, native plant restoration, and restoration of natural processes and hydrology at the creek’s mouth (NPS); (3) Realignment and reconnection of Green Gulch Creek it to Redwood Creek for the first time in many decades, providing valuable off-channel habitat for coho salmon (NPS and SF Zen Center); (4) Removal of culvert barriers for adult and juvenile steelhead in Jewel Creek (NPS land, implemented by MMWD); (5) Banducci restoration including large woody debris installation and creek realignment (2003), removal of levees and fill from floodplain (2007), and groundwater recharge improvements (2015) (NPS); Identification of high priority sites for barrier removal on Redwood Creek through the 2003 Marin County Fish Passage Assessment, leading to the installation of a new culvert connecting Kent Canyon and the mainstem of Redwood Creek and replacement of an undersized culvert under Muir Woods Road (NPS)

Management: (1) Multi-agency Coho Jumpstart program to rear and release coho salmon back into Redwood Creek starting in 2015; (2) Water releases into Lagunitas Creek to maintain streamflow for salmonids (MMWD); (3) Reduction of sedimentation as a result of the Dias Ridge restoration project (NPS), multiple projects along the Bootjack Trail (NPS and State Parks), Alice Eastwood Road culvert removal (State Parks), fire road and trail sediment reduction projects in San Geronimo/Lagunitas Watershed (MCP), and several significant projects stemming from the implementation of the MMWD 2005 Mt. Tamalpais Watershed Road and Trail Management Plan

Monitoring: Long-term life-cycle (juvenile, smolt, adult spawner/redds) monitoring of salmonids in Lagunitas and Redwood creeks (MMWD and NPS) and annual adult and smolt monitoring in the San Geronimo Valley (SPAWN)

California Red-legged Frogs

Restoration: Creation of breeding pond and backwater habitats at Muir Beach beginning in 2009 and at Banducci in 2007; (2) Relocation of egg masses and/or adult frogs to help bolster the population at the Banducci farm and Muir Beach restoration sites (NPS)

Monitoring: Annual breeding frog surveys (NPS)

Research: (1) Habitat use and movement study at Olema, Bolinas, and Redwood Creek watersheds; (2) Genetic studies to determine diversity of the Redwood Creek Watershed population (NPS and USGS)

Monitoring and Surveys: (1) Habitat and population survey in 2003 (MMWD); (2) Irregular mark and release efforts between 2004 and 2016 (MMWD); (3) Periodic turtle trapping to remove non-native turtles and to provide some data on Western Pond Turtle population sizes, age estimates, and sex ratios in each reservoir (MMWD); (4) Volunteer “Turtle Observer” program to collect age, date, time interval, weather and a series of qualitative observations about each turtle’s appearance and behavior (MMWD); (5) Turtle inventories in 1996 and 2014-present (NPS)

Birds

Restoration: Invasive plant removal and revegetation in the Redwood Creek Watershed for over 15 years